1. Field of the Invention
The invention relates to a siphoning device having particular utility as a food baster, of the type commonly know as a turkey baster. The invention is also applicable to medical, scientific and industrial applications and can be used for the separation of immiscible liquids.
2. Brief Description of the Prior Art
The prior art devices commonly known as basters do not effectively contain the liquid that has been drawn into the device. Typically, these devices expel some of whatever liquid the user is attempting to move before the device has reached the final destination. The solution to this has been to tip the baster, directing the liquid to the bulb. This, however, increases the possibility of spillage and places the generally hot contents adjacent the user""s hand.
The term baste is used in the application consistent with the definition in the American Heritage Dictionary, Third Edition, Copyright 1994, InfoSoft International, as follows: baste tr.v. basted, basting, bastes. To moisten (meat, for example) periodically with a liquid, such as melted butter or a sauce, especially while cooking baster n.
In its simplest form (hereinafter referred to as the xe2x80x98simple basterxe2x80x99) the simple baster consists of only two parts. The first part is the bulb, which is typically made of rubber or a rubber-like plastic. The bulb is generally thick and soft to allow for flexibility as the device is operated by squeezing and releasing the bulb by hand. The second part is a hollow round tube or cylinder, tapered at one end to a small opening. The bulb is attached to the tube at the wider end, with the small opening being used to collect and disperse liquids. While baking meat, to add flavoring and prevent dehydration, it is desirable to take broth or meat juices to baste the meat. The baster is employed in this endeavor by holding the device in one hand and ejecting some of the air from the bulb. The lower end of the tube is placed below the liquid surface, the bulb is released and the vacuum draws the liquid into the tube. The tube is then moved to the top of the meat being cooked, the bulb is squeezed and the liquid is ejected over the meat. In the simple baster, when the liquid is drawn into the tube, it is frequently hot. The hot liquid heats the air in the tube and the bulb, causing expansion of the air. The expansion of the air forces at least some of the liquid out the tube. It is often impossible to draw or retain enough liquid in the baster to adequately baste the meat. Attempts to contain the liquid by turning the tube over, bulb end down, can leak hot liquid in an uncontrollable and dangerous fashion. Turning the baster all the way places the bulb, filled with hot liquid, near the user""s hand and may cause burns through the flexible bulb.
The simple baster is often used to separate the meat juices into their component lighter fat and heavier water-soluble parts. When separated from the fat, the heavier water-soluble material is frequently used as a component in gravies. The heavier materials will be referred to as xe2x80x98flavoringsxe2x80x99. While it would be desirable to wait for a brief time for the fat and flavorings to separate, for distribution into different containers, this is not always feasible. The nature of the simple baster is not well suited for use as a separator because the contents begin to exit as soon as they have entered, often with outside air bubbling through and remixing the liquids to be separated. Any attempts to draw all the pan juices into the baster for separating in one operation results in mixing the pan juices, just the opposite of the desired separation.
Another shortcoming of the simple baster is the inability to measure or control the exact amount of liquid delivered by the baster. The only control over the volume entering the tube occurs when the bulb is squeezed a particular amount or the inlet pulled out of the liquid. The user must estimate how much to squeeze the bulb prior to insertion into the liquid, since squeezing the bulb after the tube has been partially filled drives the liquid out of the baster. Thus, the device cannot be operated in a cumulative manner.
The simple baster, or a similar device, can also be used for a multitude of tasks that involve moving liquids. These liquids can be hot or cold, acid or base, aqueous or not, highly fluid or partially viscous.
In summary, the prior art simple basters are deficient in at least four ways:
1. Fluid leaks due to flow under the force of gravity.
2. When hot liquid is used, air above the liquid expands and pushes the liquid out, making the handling of liquids difficult and dangerous.
3. The amount of liquid that can be drawn up is limited by the size of the bulb and the air trapped within the bulb.
4. Making exact liquid measurements are difficult, because of leaking of the device and the inability to control the amount of liquid drawn into the device.
Prior U.S. Pat. Nos. 5,875,823 and 5,638,872 to Porter disclose and claim devices that overcome prior art problems. It is an object of the present invention to provide an improved design that is less costly to manufacture and easier to use.
The invention relates to an improved siphoning device, particularly of the type used for basting foods. The device includes an elongated hollow body member having a first open tip end with a fluid flow opening and a second open end. A two-way liquid valve is positioned within said first open tip end, and air pump member is removably attached to the second end of the body member. The air pump is used to expel air from the hollow body member and to draw or siphon liquid into the hollow body member.
The two-way liquid valve has an elongated stem member and a seal member. The seal member is movably positioned within the first open tip end, and is movable between a first position and a second position. The seal member engages the interior surface of the body member proximate the first open tip when in the first position, thereby precluding fluid flow out of the hollow body member first open tip end. It disengages the interior surface of the outlet region when in the second position, thereby permitting flow into or out of the hollow body member.
The stem member has a first end and a second end, with the second end affixed to the seal member to enable the stem to travel with the seal member. The stem member""s first end extends substantially beyond the open tip end exterior of the body, so that when the seal member is in the first position, the stem""s first end extends through and substantially beyond the open tip end. When the stem""s first end is moved toward the open tip end, the seal member is moved away from the interior surface of the outlet region, enabling fluid flow.
The stem has an engagement member extending away from the stem at least at an acute angle, preferably forming an xe2x80x9cLxe2x80x9d. Pressure on the engagement member in the direction of the seal member moves the seal member out of contact with the interior wall, thereby placing the liquid valve in an open position and permitting liquid to be discharged axially from the hollow body member, through the first open tip end fluid flow opening and along the stem member.
Preferably, the air pump member is a flexible bulb releasably affixed to the second open end of the hollow body member.
Preferably, the seal member is a ball valve member having a horizontal cross-section corresponding to the first open tip end circular cross-section. Advantageously, the ball valve member has a diameter greater than the diameter of the first open tip end and has an oval vertical cross-section.
A stem shroud extends from the first open tip end, such that its proximal end is affixed to, or an extension of the tip end, and its distal end extends beyond that of the stem when the valve member is in the closed position. Thus, when the stem shroud is positioned flush against a flat surface, the stem does not contact the flat surface and the valve is closed. The engagement member is positioned and dimensioned to extend through an elongated opening in the shroud and substantially beyond the shroud. Essentially, the shroud member has a xe2x80x9cCxe2x80x9d shaped cross-section.
An air vent is provided for exhausting hot gases and as an air outlet for pumping air out of the body member and creating suction within the hollow body member. The air vent is preferably positioned proximate the elongated body second open end and has a cross-sectional area substantially less than the fluid flow opening cross-sectional area. In this manner, it functions as a one way valve by substantially restricting air flow into said body relative to fluid flow through the fluid flow opening.
The air vent preferably has a diameter in the range from at least one thirty second of an inch to three thirty seconds of and inch. Most preferably, the diameter is greater than one thirty second of an inch and less than three thirty seconds of and inch. Most preferably, the diameter is about two thirty seconds of an inch. By way of contrast, the fluid flow-opening diameter is about one quarter of an inch, and would have a range comparable to that of the air vent. The ratio of the air vent cross-sectional area to the fluid flow opening cross-sectional area must be low enough to assure that the siphoning action draws in a minimal amount of air, that is, the fluid intake is predominantly liquid entering through the fluid flow opening. A fluid flow opening has a cross-sectional area on the order of at least about 100 mm.
A vent collar is advantageously provided for directing any fluid flow out of the air vent, down and away from the user. In this manner, the user is protected from the hot gases that can be exhausted through the air vent and any inadvertent exiting of liquid, as for example, due to overfilling of the hollow body member. The vent collar is supported on the hollow body member over and spaced from the air vent, such that airflow into the body member, through the air vent, is not closed by the collar member.
A radially outward extending flange member is provided on the hollow body. The flange member is positioned between the air vent and the elongated body second open end. The vent collar has a radially inward extending flange region, dimensioned and positioned such that the vent collar flange region is supported on the hollow body flange member.
The vent collar has is cylindrical in shape, corresponding to the cylindrical shape of the body member, and has a first end proximal to the hollow body second open end and a second end distal relative to the hollow body second open end. The collar""s flange region extends from the hollow body member""s proximal end. The vent collar distal end having a radius at least about 1 mm and preferably about 2 mm greater than the radius of the elongated body member, to provide an air flow clearance.
The method of liquid transfer using the above described device includes the steps of: pumping air out of the air vent hole by constricting the air pump member; inserting the outlet region into a liquid, before or after the previous step, such that the outlet of the outlet region is below the surface of the liquid; siphoning liquid into the device, by releasing the air pump member. Once the air pump member is released, air is substantially prevented from entering the hollow body member due to the air vent""s relatively small cross-sectional area. The device is withdrawn from the outlet region from the liquid, while the two-way liquid valve restricts flow of liquid out of the device. The device is moved to a desired location. The liquid valve is activated to allow the liquid to flow from the body member to the desired location, thus dispensing at least a portion of the liquid at the desired location. The air pump is repeatedly activated while the outlet of the outlet region is below the surface of said liquid, thereby repeatedly drawing liquid into the device. During this step the vent collar protects a user from inadvertent contact with liquid that flows out of the air vent hole, and the liquid valve prevents the flow of liquid from the device while permitting fluid flow into the device.
During the operation of the device, air is expelled via the air vent hole through the step of compressing the air pump member. However, the relative dimensions of the air vent, the body member and the liquid outlet, restrict the airflow into the body member via the air vent, thus enabling the air vent to function as a one-way valve with no moving parts.
The dimension relation is critical to provide siphoning predominantly of liquid into the device and while only a relatively small amount or minimal amount of air flows into the device via the air vent hole.